Atomic Physics

Electrons

: almost mass- less particles which orbit nucleus in shells.

Thin gold foil

is bombarded with alpha particles, which are positively charged.

Isotope

: Atoms of the same element that have different numbers of neutrons e.g.

Industrial use

: to check for leaks- radioisotopes (tracers) added to oil /gas.

Geiger Müller

A(n) (GM) tube can be used to detects alpha, beta and gamma radiation.

Gamma emission

by itself causes no change in mass number or atomic number; they just emit energy.

Background

radiation: small amount of radiation around us all time because of radioactive materials in the environment.

Radioactive material

is stored in a lead container.

Nucleus

: central part of atom made of protons (positively charged) and neutrons.

Rutherford

concluded that the atom must be largely empty space, with its positive charge and most of its mass concentrated in a tiny nucleus.

Medical use

: cancer treatment (radiotherapy)- rays kill cancer cells using cobalt- 60.

Radio isotopes

are unstable atoms, which break down giving radiation.

radio isotopes

There are non- radioactive isotopes and .

Nucleus

 central part of atom made of protons (positively charged) and neutrons

Electrons

 almost mass-less particles which orbit nucleus in shells

Proton number

 number of protons in an atom

Nucleon number

 the number of nucleons (protons + neutrons) in an atom

Isotope

Atoms of the same element that have different numbers of neutrons e.g

Background radiation

small amount of radiation around us all time because of radioactive materials in the environment

Radioactive decay

 A radioisotope (unstable arrangement of neutrons and protons) is altered to make a more stable arrangement

Half-life of a radioisotope

 is the time taken for half the nuclei present in any given sample to decay